Linux-diff

NAME

diff - compare files line by line

SYNOPSIS

diff [OPTION]... FILES

DESCRIPTION

Compare FILES line by line.

Mandatory(强制性参数) arguments to long options are mandatory for short options too.

--normal: output a normal diff (the default)

-q, --brief
report only when files differ
-s, --report-identical-files
report when two files are the same

(only show the same or differ)

-c, -C NUM, --context[=NUM]
output NUM (default 3) lines of copied context
-u, -U NUM, --unified[=NUM]
output NUM (default 3) lines of unified context

-e, --ed
output an ed script

-n, --rcs
output an RCS format diff

-y, --side-by-side
output in two columns

-W, --width=NUM
output at most NUM (default 130) print columns

--left-column
output only the left column of common lines

--suppress-common-lines
do not output common lines

-p, --show-c-function
show which C function each change is in

-F, --show-function-line=RE
show the most recent line matching RE

--label LABEL
use LABEL instead of file name (can be repeated)

-t, --expand-tabs
expand tabs to spaces in output

-T, --initial-tab
make tabs line up by prepending a tab

--tabsize=NUM
tab stops every NUM (default 8) print columns

--suppress-blank-empty
suppress(压缩) space or tab before empty output lines

-l, --paginate
pass output through `pr' to paginate(分页) it

-r, --recursive
recursively compare any subdirectories found

-N, --new-file
treat absent(不存在的) files as empty

--unidirectional-new-file
treat absent first files as empty

--ignore-file-name-case
ignore case when comparing file names

--no-ignore-file-name-case
consider case when comparing file names

-x, --exclude=PAT
exclude(排除) files that match PAT

-X, --exclude-from=FILE
exclude files that match any pattern in FILE

-S, --starting-file=FILE
start with FILE when comparing directories

--from-file=FILE1
compare FILE1 to all operands; FILE1 can be a directory

--to-file=FILE2
compare all operands to FILE2; FILE2 can be a directory

-i, --ignore-case
ignore case differences in file contents

-E, --ignore-tab-expansion
ignore changes due to tab expansion(扩张)

-Z, --ignore-trailing-space
ignore white space at line end

-b, --ignore-space-change
ignore changes in the amount of white space

-w, --ignore-all-space
ignore all white space

-B, --ignore-blank-lines
ignore changes whose lines are all blank(空白)

-I, --ignore-matching-lines=RE
ignore changes whose lines all match RE

-a, --text
treat all files as text

--strip-trailing-cr
strip trailing carriage return on input(带状拖尾的回车输入)

-D, --ifdef=NAME
output merged file with `#ifdef NAME' diffs

--GTYPE-group-format=GFMT
format GTYPE input groups with GFMT

--line-format=LFMT
format all input lines with LFMT

--LTYPE-line-format=LFMT
format LTYPE input lines with LFMT

Format

These format options provide fine-grained control over the output of diff, generalizing -D/--ifdef.

LTYPE is 'old', 'new', or 'unchanged'.
GTYPE is LTYPE or `changed'.

GFMT (only) may contain:

%< lines from FILE1

%> lines from FILE2

%= lines common to FILE1 and FILE2

%[-][WIDTH][.[PREC]]{doxX}LETTER
printf-style spec for LETTER

LETTERs are as follows for new group, lower case for old group:

F first line number

L last line number

N number of lines = L-F+1

E F-1

M L+1

%(A=B?T:E)
if A equals B then T else E

LFMT (only) may contain:

%L contents of line

%l contents of line, excluding any trailing newline

%[-][WIDTH][.[PREC]]{doxX}n
printf-style spec for input line number

Both GFMT and LFMT may contain:

%% %

%c'C' the single character C

%c'\OOO'
the character with octal code OOO

C the character C (other characters represent themselves)

-d, --minimal
try hard to find a smaller set of changes

--horizon-lines=NUM
keep NUM lines of the common prefix and suffix

--speed-large-files
assume large files and many scattered small changes

--help display this help and exit

-v, --version
output version information and exit

FILES are 'FILE1 FILE2' or 'DIR1 DIR2' or 'DIR FILE...' or 'FILE... DIR'. If --from-file or
--to-file is given, there are no restrictions on FILE(s). If a FILE is '-', read standard
input. Exit status is 0 if inputs are the same, 1 if different, 2 if trouble.